Tool for setting screw-anchors.



C.-N. ACKERMANL J. L. JOHNSON.

TOOL FOR SETTING SCREW ANCHORS.

APPLICATION FILEDMAR. 20, 1915.

15164303. 7 1 Patented Dec. 21,

awfim W UNITED STATES PATENT OFFICE.

CHARLES N. ACKERMAN AND JOHN L. :foHNso'N, or CHICAGO, ILLINOIS.

TOOL FOR SETTING SGIftEW-ANCHORS.

' Specification ofLetters Patent.

Patented Dec. 21, 1915.

Application filed March 20, 1915. Serial No. 15,981.

To all whom it may concern Be it known that we, CHARLES N. ACKER- MAN and JOHN L. JOHNSON, citizens of the United States, residing at Chicago, in the county of Cook and State of Illinois,have invented certain new and useful Improvements in Tools for SettingScrew-Anchors, of which the following is a specification.

Our invention relates to a tool for setting screw anchors and the like, and in some of its features particularly to a driving tool for such purpose.

A particular object of our invention is to provide a driving tool for setting a screw anchor that consists of an externally tapered, screw receiving body surrounded by a duotile sleeve that may be distorted or swaged to wedge between the rigid body and the peripheral wall of an anchor-receiving recess.

Particular objects of our invention are to provide a tool that may be most facilely employed for the swaging or distortion of the ductile sleeve, that will insure proper and uniform application of the setting forcev to all portions of the sleeve; that will tend to prevent distortion of the sleeve in such fashion as to interfere with the thread bore of the body; and that will otherwise aid in the best setting of the anchor.

' In the drawings wherein we have illustrated embodiments of our invention for purposes of full disclosure thereof, Figure 1 is a broken View showing a fragment of a tool embodying our invention in association with a screw anchor to be set. I Figs. 2 and 3 illustrate by similar broken views the intended use of the tool. Fig. 4 is a sectional view showing a modified tool embodying our invention, illustrated in coacting relation with an anchor and Figs. 5 and 6 illustrate 7 in sectional view and in elevation an anchorage device as it may beset by the use of-said tool.

. A screw anchor of the sort above suggested is illustrated as comprising a body 10, and a sleeve 14. 'The body 10 is preferably rigid, made of brass or steel, with a screw receiving bore 11 made axially through its front end and opening into a bell or conical recess 11' at the rear end. Said body is externally tapered toward its front end,

preferably with a slight pitch 12 through out the major portion of its length and with a more abrupt pitch 13 adjacent the bell recessed end thereof, so giving a biconoidal effect. The ductile sleeve 14, surrounding body 10, is preferably of lead, and preferably is sufliciently wedgedon the body, preliminarily, to be handled therewith as a unit. Such sleeve is preferably cylindrical externally and of about the maximum diameter of the body, and has a normal bore 15 of approximately the diameter of the front extremity of the body. Before distortion the sleeve overhangs the front end of the anchor and stops short of the rear endpreferably near the beginning of abrupt pitch 13. Such a screw-receptive anchor may be seated in a recess 16 in a structure 17 by placing the anchor device in the recess so that the rear end of the body rests against the bottom 18 of the recess and then applying force to the ductile sleeve 14 to force it along the flaring body, so to enlarge its diameter that it will grip against the side walls of saidrecess. it is for this last named purpose that our tool, indicated in general at 20, is employed. Said tool, in the form shown in Figs. 1 to 3, comprises a body 21 of diameter suitable to make it convenient pressure surface 23, and of smaller diameter adequate to slip neatly. within the screw threaded bore 11 of the anchor. Thus there is left between the pilot and the pressure surface a clearance space 25 within the bod slightly wider than the front end of the body 10 of the anchor.

It is preferable, (althoughit is not essential,) that the pressure surface shall have small recesses 26 (or projections) that may pialire the form of suitable lettering or the In using the tool the pilot is slipped into the screw bore 11 and the tool may thus be used as an implement for inserting the anchor structure into its recess in, the wall.

When'the anchor is bottomed in the socket,

the end 22 ofthe tool is hammered upon,

driving the ductile sleeve rearwardly on the flaring rigid body and so spreading it laterally until it exerts a firm lateral grip upon the encompassing walls vof the recess 16. By accurate work in drilling the recesses of suitable diameter, and just thedepth of the anchor body in material of uniform density, such as'slate or metal, the anchors may be made to exert an efi'ective grip just when the ductile sleeve is swa ed in substantially flush with the end of the socket and with the end of the body 10, as shown in Figs. 2 and 6. But it often happens,

owing to oversizing of the recess diameters, irregularity in thecontour of the recess, and other causes, that in orderto exert the required grip the lead must be-swaged beyond this ideal point, producing a result somewhat as shown in Fig. 3, and it will be observed that the provision' of a clearance space 25, somewhat larger than the anchorbody-end and running back into the body 21 of the tool, enables the pressure surface of, the tool to be advanced well over the tapered end of the body 10 of the anchor to complete the desired swaging operation.

' In Fig. t the modified embodiment shown hasitspilot 24: projecting from a yielding filler-block 26 that nearly fills the clearance space 25' in the body of the tool, said block 26 working against the sprin 27' and the front end of the block aifordmgan annular shoulder 28 that may abut against the end of the anchor body 10. The operation of this form of tool will be the same as has heretofore been described, savethatthepilot '24 does not move with the tool body after the hammering operation commences, but maintains its relation to'anchor body 10 and therefore yields relative to the tool body as the latter advances. It will be seen, of course, that the pilot-carrying block may retreat into the body 21 so that the clearance space 25"within the body may pass 1 over the forward. end of the anchor body 10 as heretofore described. It will be apparent that this last mentioned form of device provides in its portion 26 a filler that will prevent radial inflow'fof the metal of the ductile sleeve tosuch point as possibly to interferewith the freedom ofrthe end of anchor body- 10; and for this reason it is a par-- ticularly desirable form for use in some cases where the anchor initially fits very snugly in its recess and swaging to produce a very tight grip of the anchor is desired. However, we find in practice that the simpler form of construction, shown in Figs. 1 to 3, is efiicacious for most purposes, and. is commercially desirable for its cheapness. i

It will be observed that the normally-protruding pilot, effecting preliminarily a relatively long bearing in the screw bore, not

the unbalanced driving force was exerted inwardly toward the screw bore. Also the provision of recesses (or projections) .26 on the pressure surface insures'that during thesetting operation there will be an appreciable friction tendency between the sleeve'and tool to holdthe tool in continuing contact with the sleeve surface, owing to the swaging of the metal into the recesses, and also an appreciable .tendency to prevent any rotary movement of the pilot in the-threaded bore, that might tend to grind or distort the crests of the screw thread teeth.

While We have herein described in some detail a particular embodiment of our inntion in a driving tool it will be understood that in its broader aspects manychanges in the construction might be made without departure from the spirit of our invention and Within the scope of the appended claims.

- Having described our invention, what we claim is: v

l. 'A setting tool for screw anchors comprising a pressure portion for swaging and a normally-protruding pilot portion for guidance, there being between the outer pcriphery of the pilot and inner periphery of the pressure surface a clearance space extending back into the body of the tool.

2. A tool of-the character described comprising a body portion having an end adapt ed to be hammer driven, and an opposite end providing an annular pressure surface, and a pilot protruding beyond said pressure surface, centrally located with respect thereto, and spaced apart therefrom.

3. A setting tool for screw anchors comprising a body having an annular pressure surface at one end, and a clearance space Within said pressure surface, and a pilot adapted to engage the anchor bore, located centrally within the clearance space.

4:. An anchor-setting tool of the character described comprising a body. having a. pres sure surface for swaging, and a smooth, cy- V In testimony whereof we hereunto set our lindrical, normally-protruding pilot portion hands. for guidance, there being between the pilot CHARLES N. ACKERMAN. and the pressure surface an annular clear- JOHN L. JOHNSON. 5 ance space extending back into the body of In the presence of the tool, and adapted to receive the end of STANLEY WV. CooK,

un anchor. MARY F. ALLEN. 

